“Contrails (short for “condensation trails”) or vapour trails are artificial clouds that are the visible trails of condensed water vapour made by the exhaust of aircraft engines. As the hot exhaust gases cool in the surrounding air they may precipitate a cloud of microscopic water droplets or, if the air is cold enough, tiny ice crystals”. – Wikipedia

Photo: An airplane leaves a vapor trail as it flies in front of he moon on January 17, 2007 above Hanover, Germany. (Photo by Alexander Hassenstein/Getty Images)

Impala pictured in the Kruger National Park on December 7, 2007 in Mpumalanga, South Africa. (Photo by Warren Little/Getty Images)

Umbrellas are placed over the statute of the Beatles, during a photocall, on Liverpool's waterfront, in Liverpool, England, Wednesday, March 22, 2017. The city of Liverpool is getting set to celebrate the half-centenary of “Sgt. Pepper's Lonely Hearts Club Band”, one of the most influential albums by local heroes The Beatles. (Photo by Peter Byrne/PA Wire via AP Photo)

A man performs a split as he practices Kung Fu at Beihai Park in Beijing, China August 20, 2017. (Photo by Reuters/China Stringer Network)

Most of people who have visited Bali have seen the cockfighting popular among the locals. A little-known but no less ardent hobby among Bali’s farming community is cricket fighting, or mejangkrikang. The insects face off inside bamboo tubes known as bumbung, and bets are placed on the bouts, which typically last two minutes. Here: a cricket breeder shows his two adult fighter crickets on a bamboo tubes called Bumbung. (Photo by A. A. Gde Agung/JG Photo)

May Matthews (left) and Romy Clark from Bonhams Edinburgh carry a carved wooden model of an Atlantic Salmon by Rogers Brookes (estimate £1,500-2,000) during a photo call for the upcoming Home and Interiors sale, and Sporting and Wildlife sale, at Bonhams, Edinburgh, on September 16, 2020. (Photo by Jane Barlow/PA Images via Getty Images)

A Russian peacekeeper shouts “No pictures!” at a checkpoint outside the city of Stepanakert on November 13, 2020, during a ceasefire in the military conflict between Armenia and Azerbaijan over the breakaway region of Nagorno-Karabakh. Russian began deploying 2,000 peacekeepers to Nagorno-Karabakh on November 10 after Armenia and Azerbaijan agreed a peace deal to end weeks of fierce fighting over the disputed region. (Photo by Alexander Nemenov/AFP Photo)

This picture taken on January 14, 2021 and released from North Korea's official Korean Central News Agency (KCNA) on January 15 shows Pak Jong Chon, chief of the General Staff of the Korean People's Army, during a military parade celebrating the 8th Congress of the Workers' Party of Korea (WPK) in Pyongyang. (Photo by KCNA via KNS/AFP Photo)